A UGA termination suppression tRNATrp active in rabbit reticulocytes

Abstract
A tRNATrp was purified from rabbit reticulocytes which suppresses the UGA termination codon of β-haemoglobin mRNA. Evidence is presented that the β-haemoglobin readthrough protein is found in reticulocyte translations and intact cells. Some natural readthrough proteins perform essential functions; they are synthesised through suppression of UGA or UAG but not UAA termination codons.